1. Field of the Invention
The present invention relates to a reciprocating sheet pusher for sheet feeding or delivering a topmost sheet seriatimly from a stack of sheets ejected from a sheet receiving storage bin.
2. Description of the Prior Art
In the field of sheet feeding or delivering, it has been a general practice to seriatimly eject sheets from sheet receiving storage bins, such as in a collator. Mechanical structure necessary to eject a topmost sheet from a stack of sheets is usually complex and cumbersome in addition to being less than satisfactory in ejecting one sheet at a time.
Sheet feeders which push paper despite such inherent difficulties as pushing more than one sheet at a time are known and used in the art taking many forms of construction.
Mestre, U.S. Pat. No. 3,208,746; issued Sept. 28, 1965, discloses a sheet feeding arm pivotally mounted at one end and a pair of rotating sheet feed rolls at the other end. The sheet feed rolls are carried on sleeves which are releasably anchored to roll shafts. A drive system is provided between the pivot shaft and roll shaft so that when the roll shaft is rotated, sheet feed rolls push a sheet forward and outward away from a pile of sheets carried by the sheet bin. As the pusher arm doesn't reciprocate, this prior art does not directly relate to the invention.
Another prior art device uses an inclined sheet receiving bin having a conventional sheet pusher arm which locks a first roller against movement in a push direction and rolls in a reverse direction. A second roller mounted on the sheet pusher arm rolls in a groove in the sheet receiving bin which eliminates any problem of a locked roller jamming in the bin on a sheet mis-feed or where there are no sheets in the bin is the sheet pusher arm partially falls into the groove. The second roller rides on the bin supporting the first roller within the groove. This prior art device requires a special design of sheet receiving storage bin in combination with the special requirements of the sheet pusher arm. The present invention can be used with any sheet receiving storage bin.
Other prior art devices using sheet pusher arms to eject sheets seriatim out of a sheet receiving storage bins are U.S. Pat. Nos. 3,669,442 issued June 16, 1972; and 3,891,202 issued June 24, 1975. These patents disclose ejection feet which do not relate to the present invention.